Thinking as a sales team, what are the most impactful activities that Marketing can do to help you in a B2B enterprise sale? Webinars? Events? Content? something else? Marketers want to drive success, and they don't always connect with seller needs.

In my experience, the B2B market relies heavily on relationships and referrals.
For established products, a good product description with links to implemented best practices can work.
However, if you're exploring a new technology and its use cases, I believe promoting POCs in close collaboration with a few representative partners is the most effective way to generate attention and drive final product development.
This gives us the opportunity to doubly accelerate the process: on the one hand, the customer can explore new opportunities, and on the other, we can understand their real needs and define future potential market.

From my expericene: Cut the silos and start the collaboration between the departments. From a marketing perspective, it's a bit naive to think that the marketing department should do all by themselves and try to understand the needs of sales, and vice versa for sales. Involve sales, allocate tasks to them, team up and craft compelling client cases, use these for webinars, create a joint plan and goals for events and follow up. Content make the sales rep outline what should be written and then marketing support with tuning etc